scholarly journals Zearalenone-Induced Interaction between PXR and Sp1 Increases Binding of Sp1 to a Promoter Site of the eNOS, Decreasing Its Transcription and NO Production in BAECs

Toxins ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 421 ◽  
Author(s):  
Hyeon-Ju Lee ◽  
Jung-Hyun Park ◽  
Se-Young Oh ◽  
Du-Hyong Cho ◽  
Suji Kim ◽  
...  
Keyword(s):  
Promoter Region ◽  
Ex Vivo ◽  
Pregnane X Receptor ◽  
Proximal Region ◽  
No Production ◽  
Enos Expression ◽  
Aortic Endothelial Cells ◽  
Specificity Protein 1 ◽  
Specificity Protein ◽  
Ex Vivo Study

Zearalenone (ZEN) is a non-steroidal mycotoxin that has various toxicological impacts on mammalian health. Here, we found that ZEN significantly affected the production of nitric oxide (NO) and the expression of endothelial NO synthase (eNOS) of bovine aortic endothelial cells (BAECs). A promoter analysis using 5′-serially deleted human eNOS promoter revealed that the proximal region (−135 to +22) was responsible for ZEN-mediated reduction of the human eNOS promoter activity. This effect was reversed by mutation of two specificity protein 1 (Sp1) binding elements in the human eNOS promoter. A chromatin immunoprecipitation assay revealed that ZEN increased Sp1 binding to the bovine eNOS promoter region (−113 to −12), which is homologous to −135 to +22 of the human eNOS promoter region. We also found that ZEN promoted the binding of the pregnane X receptor (PXR) to Sp1 of the bovine eNOS, consequently decreasing eNOS expression. This reduction of eNOS could have contributed to the decreased acetylcholine-induced vessel relaxation upon ZEN treatment in our ex vivo study using mouse aortas. In conclusion, our data demonstrate that ZEN decreases eNOS expression by enhancing the binding of PXR-Sp1 to the eNOS promoter, thereby decreasing NO production and potentially causing vessel dysfunction.

Transcription factors YY1, Sp1 and Sp3 modulate dystrophin Dp71 gene expression in hepatic cells

2016 ◽  
Vol 473 (13) ◽  
pp. 1967-1976 ◽  
Author(s):  
Katia Peñuelas-Urquides ◽  
Carolina Becerril-Esquivel ◽  
Laura C. Mendoza-de-León ◽  
Beatriz Silva-Ramírez ◽  
José Dávila-Velderrain ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Promoter Region ◽  
Site Directed Mutagenesis ◽  
Cellular Processes ◽  
Specificity Protein 1 ◽  
Hepatic Cells ◽  
Dna Elements ◽  
Yin And Yang ◽  
Specificity Protein ◽  
Flanking Regions

Dystrophin Dp71, the smallest product encoded by the Duchenne muscular dystrophy gene, is ubiquitously expressed in all non-muscle cells. Although Dp71 is involved in various cellular processes, the mechanisms underlying its expression have been little studied. In hepatic cells, Dp71 expression is down-regulated by the xenobiotic β-naphthoflavone. However, the effectors of this regulation remain unknown. In the present study we aimed at identifying DNA elements and transcription factors involved in Dp71 expression in hepatic cells. Relevant DNA elements on the Dp71 promoter were identified by comparing Dp71 5′-end flanking regions between species. The functionality of these elements was demonstrated by site-directed mutagenesis. Using EMSAs and ChIP, we showed that the Sp1 (specificity protein 1), Sp3 (specificity protein 3) and YY1 (Yin and Yang 1) transcription factors bind to the Dp71 promoter region. Knockdown of Sp1, Sp3 and YY1 in hepatic cells increased endogenous Dp71 expression, but reduced Dp71 promoter activity. In summary, Dp71 expression in hepatic cells is carried out, in part, by YY1-, Sp1- and Sp3-mediated transcription from the Dp71 promoter.

scholarly journals Progesterone promotes endothelial nitric oxide synthase expression through enhancing nuclear progesterone receptor-SP-1 formation

2020 ◽  
Vol 319 (2) ◽  
pp. H341-H348
Author(s):  
Yuehua You ◽  
Wanying Tan ◽  
Yongzheng Guo ◽  
Minghao Luo ◽  
Fei-fei Shang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Progesterone Receptor ◽  
Endothelial Nitric Oxide Synthase ◽  
Dependent Manner ◽  
Enos Expression ◽  
Specificity Protein 1 ◽  
Specificity Protein ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Progesterone directly upregulated endothelial nitric oxide synthase (eNOS) expression in human endothelial cells. Progesterone augmented eNOS promoter activity through a progesterone receptor A- and specificity protein-1-dependent manner. Antagonism of the progesterone receptor reduced eNOS expression and impaired vasodilation in rats.

scholarly journals Phytoestrogen Genistein Up-Regulates Endothelial Nitric Oxide Synthase Expression Via Activation of cAMP Response Element-Binding Protein in Human Aortic Endothelial Cells

Endocrinology ◽  
2012 ◽  
Vol 153 (7) ◽  
pp. 3190-3198 ◽  
Author(s):  
Hongwei Si ◽  
Jie Yu ◽  
Hongling Jiang ◽  
Hazel Lum ◽  
Dongmin Liu
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Nitric Oxide Synthase ◽  
No Production ◽  
Enos Expression ◽  
Camp Response Element ◽  
Aortic Endothelial Cells ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Human Aortic Endothelial Cells

We previously reported that genistein, a phytoestrogen, up-regulates endothelial nitric oxide synthase (eNOS) and prevents hypertension in rats that are independent of estrogen signaling machinery. However, how genistein regulates eNOS expression is unknown. In the present study, we show that genistein enhanced eNOS expression and NO synthesis in primary human aortic endothelial cells. Inhibition of extracellular signal regulated kinase, phosphoinositol-3 kinase, or protein kinase C did not affect genistein-enhanced eNOS expression and NO synthesis. However, chemical inhibition of protein kinase A (PKA) or adenoviral transfer of the specific endogenous PKA inhibitor gene completely abolished PKA activity and genistein-stimulated eNOS expression and NO production. Accordingly, genistein induced PKA activity and subsequent phosphorylation of cAMP response element (CRE)-binding protein (CREB) at Ser133. Suppression of CREB by small interfering RNA transfection abolished genistein-enhanced eNOS expression and NO production. Consistently, deletion of the CRE site within human eNOS promoter eliminated genistein-stimulated eNOS promoter activity. These findings provide the first evidence to our knowledge that genistein may play a beneficial role in vascular function through targeting the PKA/CREB/eNOS/NO signaling pathway.

P729The functional relevance of bile acids in the improvement of HDL-mediated endothelial protection after bariatric surgery

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A Jomard ◽  
O Chavez-Talavera ◽  
A Tailleux ◽  
M Bueter ◽  
A Taheri ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Bile Acids ◽  
Ex Vivo ◽  
Function Analysis ◽  
Farnesoid X Receptor ◽  
High Density Lipoproteins ◽  
Morbidly Obese ◽  
No Production ◽  
Obese Patients ◽  
Aortic Endothelial Cells

Abstract Introduction Roux-en-Y gastric bypass (RYGB) reduces cardiovascular mortality. We showed that high density lipoproteins (HDL)-mediated vasoprotection is improved early after RYGB. Circulating BAs increase upon RYGB and contribute to the weight-loss independent metabolic improvements after surgery. Bile acids (BA) are signaling molecules increasingly recognized as regulators of cardiometabolic homeostasis. BAs circulate in the blood either free or bound to albumin and HDL. The signaling role of HDL-bound BAs (HDL-BAs) is unknown. Indeed, HDL may facilitate BA delivery directly to endothelial cells where BA may synergize with HDL to promote vasoprotection. Purpose We studied whether RYGB changes the composition of HDL-BA and whether HDL functional properties may be modulated by specific BA bound to HDL. Methods HDL were isolated by ultracentrifugation from 29 morbidly obese patients before and 1 year after RYGB. The HDL-BA composition was determined by liquid chromatography-mass spectrometry (LC/MS-MS) and HDL vasoprotective properties were evaluated ex-vivo in human aortic endothelial cells (HAEC). The size and abundance of HDL particles were determined by NMR spectroscopy in plasma. Results The increase in total BA concentrations observed in plasma 1 year after RYGB also translated into higher concentrations (up to 25%) of BA bound to HDL. Moreover, obesity-induced HDL dysfunction was reversed after surgery, as shown by improved HDL-mediated endothelial NO production, anti-apoptotic effects and cholesterol efflux capacity. The size function analyses showed a post-operative shift towards larger HDL. After RYGB there was a remodeling of BA bound to HDL, which are either agonists of the endothelial nuclear farnesoid X receptor (FXR), e.g. chenodeoxy-CA (CDCA), cholic acid (CA) or for the membrane TGR5 receptor, e.g. deoxy-CA (DCA). The composition-function analysis revealed that among all BA subclasses, the specific enrichment in CA and in CDCA bound to HDL correlated with an improved endothelial anti-apoptotic capacity of HDL (R −0.52, p=0.006 for CA-HDL and R −0.35, p=0.07 for CDCA-HDL). Further, the exogenous loading of CA onto healthy native HDL isolated from human serum significantly enhanced their endothelial anti-apoptotic function. In the case of obese, dysfunctional, pro-apoptotic HDL, exogenous CA loading was able to restore HDL anti-apoptotic function. Conclusion Exogenous loading of CA restored HDL anti-apoptotic function of HDL from obese patients mimicking the beneficial remodeling of BA bound to HDL observed after RYGB. These results suggest a crucial interaction between endothelial cells and BA in the improvement of HDL's vasoprotective properties. Acknowledgement/Funding Swiss national Science Foundation Ambizione and PRIMA grant to EO

scholarly journals Blunted flow-mediated responses and diminished nitric oxide synthase expression in lymphatic thoracic ducts of a rat model of metabolic syndrome

2016 ◽  
Vol 310 (3) ◽  
pp. H385-H393 ◽  
Author(s):  
Scott D. Zawieja ◽  
Olga Gasheva ◽  
David C. Zawieja ◽  
Mariappan Muthuchamy
Keyword(s):  
Nitric Oxide ◽  
Metabolic Syndrome ◽  
Rat Model ◽  
Ex Vivo ◽  
No Synthase ◽  
Frequency Regulation ◽  
No Production ◽  
Ros Scavenging ◽  
Enos Expression ◽  
Contraction Frequency

Shear-dependent inhibition of lymphatic thoracic duct (TD) contractility is principally mediated by nitric oxide (NO). Endothelial dysfunction and poor NO bioavailability are hallmarks of vasculature dysfunction in states of insulin resistance and metabolic syndrome (MetSyn). We tested the hypothesis that flow-dependent regulation of lymphatic contractility is impaired under conditions of MetSyn. We utilized a 7-wk high-fructose-fed male Sprague-Dawley rat model of MetSyn and determined the stretch- and flow-dependent contractile responses in an isobaric ex vivo TD preparation. TD diameters were tracked and contractile parameters were determined in response to different transmural pressures, imposed flow, exogenous NO stimulation by S-nitro- N-acetylpenicillamine (SNAP), and inhibition of NO synthase (NOS) by l-nitro-arginine methyl ester (l-NAME) and the reactive oxygen species (ROS) scavenging molecule 4-hydroxy-tempo (tempol). Expression of endothelial NO synthase (eNOS) in TD was determined using Western blot. Approximately 25% of the normal flow-mediated inhibition of contraction frequency was lost in TDs isolated from MetSyn rats despite a comparable SNAP response. Inhibition of NOS with l-NAME abolished the differences in the shear-dependent contraction frequency regulation between control and MetSyn TDs, whereas tempol did not restore the flow responses in MetSyn TDs. We found a significant reduction in eNOS expression in MetSyn TDs suggesting that diminished NO production is partially responsible for impaired flow response. Thus our data provide the first evidence that MetSyn conditions diminish eNOS expression in TD endothelium, thereby affecting the flow-mediated changes in TD lymphatic function.

Transcriptional regulation of the human manganese superoxide dismutase gene: the role of specificity protein 1 (Sp1) and activating protein-2 (AP-2)

2002 ◽  
Vol 362 (2) ◽  
pp. 401-412 ◽  
Author(s):  
Yong XU ◽  
Sureerut PORNTADAVITY ◽  
Daret K. ST CLAIR
Keyword(s):  
Binding Sites ◽  
Promoter Region ◽  
Manganese Superoxide Dismutase ◽  
Expression Vector ◽  
Binding Motifs ◽  
Specificity Protein 1 ◽  
Manganese Superoxide ◽  
Negative Role ◽  
Specificity Protein

Manganese superoxide dismutase (MnSOD) plays an important role in regulating cellular redox conditions. Expression of MnSOD has been shown to protect against damage by oxidative stress and to suppress the malignant phenotype of human cancer cells. We have previously cloned the human MnSOD (SOD2) gene and analysed its 5′ proximal promoter, which has been characterized by a lack of a TATA or CAAT box and the presence of multiple GC boxes. To define further the molecular mechanisms for the regulation of MnSOD expression, multiple transcription factor-binding motifs containing overlapping specificity protein 1 (Sp1)- and activator protein (AP)-2-binding sites were identified by DNase I footprinting analysis. Functional studies in three cell lines with different levels of Sp1 and AP-2 proteins suggested that the cellular levels of these proteins may differentially regulate transcription via GC-binding motifs in the human SOD2 promoter. Co-transfection of an Sp1 expression vector resulted in an increase in the transcription of the promoter-driven reporter gene. In contrast, co-transfection of the AP-2 expression vector caused a decrease in transcription. Direct mutagenesis analysis of Sp1- and AP-2-binding sites showed that Sp1 is essential for transcription of the human SOD2 gene, whereas AP-2 plays a negative role in the transcription. Immunoprecipitation of Sp1 and AP-2 proteins demonstrated that Sp1 interacts with AP-2 in vivo. Two-hybrid analysis revealed that interaction between Sp1 and AP-2 plays both a positive and negative role in the transcription of the reporter gene in vivo. Taken together, our data indicate that AP-2 down-regulates transcription of the human SOD2 gene via its interaction with Sp1 within the promoter region. These findings, coupled with our previous observation that several cancer cell lines have mutations in the promoter region of the human MnSOD gene, which lead to an increase in an AP-2-binding site and a decrease in the promoter activity, signal the importance of understanding the promoter structure and the regulation of the human SOD2 gene by Sp1 and AP-2.

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